File: | src/lib/libusbhid/parse.c |
Warning: | line 560, column 5 Value stored to 'report_id' is never read |
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1 | /* $OpenBSD: parse.c,v 1.12 2020/06/05 00:51:56 jsg Exp $ */ |
2 | /* $NetBSD: parse.c,v 1.2 2001/12/29 20:44:22 augustss Exp $ */ |
3 | |
4 | /* |
5 | * Copyright (c) 1999, 2001 Lennart Augustsson <augustss@netbsd.org> |
6 | * All rights reserved. |
7 | * |
8 | * Redistribution and use in source and binary forms, with or without |
9 | * modification, are permitted provided that the following conditions |
10 | * are met: |
11 | * 1. Redistributions of source code must retain the above copyright |
12 | * notice, this list of conditions and the following disclaimer. |
13 | * 2. Redistributions in binary form must reproduce the above copyright |
14 | * notice, this list of conditions and the following disclaimer in the |
15 | * documentation and/or other materials provided with the distribution. |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
27 | * SUCH DAMAGE. |
28 | */ |
29 | |
30 | #include <stdlib.h> |
31 | #include <string.h> |
32 | |
33 | #include <dev/usb/usb.h> |
34 | #include <dev/usb/usbhid.h> |
35 | |
36 | #include "usbhid.h" |
37 | #include "usbvar.h" |
38 | |
39 | #define MAXUSAGE100 100 |
40 | #define MAXPUSH4 4 |
41 | #define MAXID64 64 |
42 | #define ITEMTYPES3 3 |
43 | |
44 | struct hid_pos_data { |
45 | int32_t rid; |
46 | uint32_t pos[ITEMTYPES3]; |
47 | }; |
48 | |
49 | struct hid_data { |
50 | const uint8_t *start; |
51 | const uint8_t *end; |
52 | const uint8_t *p; |
53 | struct hid_item cur[MAXPUSH4]; |
54 | struct hid_pos_data last_pos[MAXID64]; |
55 | uint32_t pos[ITEMTYPES3]; |
56 | int32_t usages_min[MAXUSAGE100]; |
57 | int32_t usages_max[MAXUSAGE100]; |
58 | int32_t usage_last; /* last seen usage */ |
59 | uint32_t loc_size; /* last seen size */ |
60 | uint32_t loc_count; /* last seen count */ |
61 | uint8_t kindset; /* we have 5 kinds so 8 bits are enough */ |
62 | uint8_t pushlevel; /* current pushlevel */ |
63 | uint8_t ncount; /* end usage item count */ |
64 | uint8_t icount; /* current usage item count */ |
65 | uint8_t nusage; /* end "usages_min/max" index */ |
66 | uint8_t iusage; /* current "usages_min/max" index */ |
67 | uint8_t ousage; /* current "usages_min/max" offset */ |
68 | uint8_t susage; /* usage set flags */ |
69 | int32_t reportid; /* requested report ID */ |
70 | struct hid_item savedcoll; /* save coll until we know the ID */ |
71 | uint8_t hassavedcoll; |
72 | }; |
73 | |
74 | static void |
75 | hid_clear_local(hid_item_t *c) |
76 | { |
77 | |
78 | c->usage = 0; |
79 | c->usage_minimum = 0; |
80 | c->usage_maximum = 0; |
81 | c->designator_index = 0; |
82 | c->designator_minimum = 0; |
83 | c->designator_maximum = 0; |
84 | c->string_index = 0; |
85 | c->string_minimum = 0; |
86 | c->string_maximum = 0; |
87 | c->set_delimiter = 0; |
88 | } |
89 | |
90 | static void |
91 | hid_switch_rid(struct hid_data *s, struct hid_item *c, int32_t next_rID) |
92 | { |
93 | uint8_t i, j; |
94 | |
95 | /* check for same report ID - optimise */ |
96 | |
97 | if (c->report_ID == next_rID) |
98 | return; |
99 | |
100 | /* save current position for current rID */ |
101 | |
102 | if (c->report_ID == 0) { |
103 | i = 0; |
104 | } else { |
105 | for (i = 1; i != MAXID64; i++) { |
106 | if (s->last_pos[i].rid == c->report_ID) |
107 | break; |
108 | if (s->last_pos[i].rid == 0) |
109 | break; |
110 | } |
111 | } |
112 | if (i != MAXID64) { |
113 | s->last_pos[i].rid = c->report_ID; |
114 | for (j = 0; j < ITEMTYPES3; j++) |
115 | s->last_pos[i].pos[j] = s->pos[j]; |
116 | } |
117 | |
118 | /* store next report ID */ |
119 | |
120 | c->report_ID = next_rID; |
121 | |
122 | /* lookup last position for next rID */ |
123 | |
124 | if (next_rID == 0) { |
125 | i = 0; |
126 | } else { |
127 | for (i = 1; i != MAXID64; i++) { |
128 | if (s->last_pos[i].rid == next_rID) |
129 | break; |
130 | if (s->last_pos[i].rid == 0) |
131 | break; |
132 | } |
133 | } |
134 | if (i != MAXID64) { |
135 | s->last_pos[i].rid = next_rID; |
136 | for (j = 0; j < ITEMTYPES3; j++) |
137 | s->pos[j] = s->last_pos[i].pos[j]; |
138 | } else { |
139 | for (j = 0; j < ITEMTYPES3; j++) |
140 | s->pos[j] = 0; /* Out of RID entries. */ |
141 | } |
142 | } |
143 | |
144 | hid_data_t |
145 | hid_start_parse(report_desc_t d, int kindset, int id) |
146 | { |
147 | struct hid_data *s; |
148 | |
149 | s = calloc(1, sizeof *s); |
150 | if (s == NULL((void *)0)) |
151 | return (NULL((void *)0)); |
152 | s->start = s->p = d->data; |
153 | s->end = d->data + d->size; |
154 | s->kindset = kindset; |
155 | s->reportid = id; |
156 | s->hassavedcoll = 0; |
157 | return (s); |
158 | } |
159 | |
160 | void |
161 | hid_end_parse(hid_data_t s) |
162 | { |
163 | |
164 | if (s == NULL((void *)0)) |
165 | return; |
166 | |
167 | free(s); |
168 | } |
169 | |
170 | static uint8_t |
171 | hid_get_byte(struct hid_data *s, const uint16_t wSize) |
172 | { |
173 | const uint8_t *ptr; |
174 | uint8_t retval; |
175 | |
176 | ptr = s->p; |
177 | |
178 | /* check if end is reached */ |
179 | if (ptr == s->end) |
180 | return (0); |
181 | |
182 | /* read out a byte */ |
183 | retval = *ptr; |
184 | |
185 | /* check if data pointer can be advanced by "wSize" bytes */ |
186 | if ((s->end - ptr) < wSize) |
187 | ptr = s->end; |
188 | else |
189 | ptr += wSize; |
190 | |
191 | /* update pointer */ |
192 | s->p = ptr; |
193 | |
194 | return (retval); |
195 | } |
196 | |
197 | #define REPORT_SAVED_COLLdo { if (s->hassavedcoll) { *h = s->savedcoll; h->report_ID = c->report_ID; s->hassavedcoll = 0; return (1); } } while (0) \ |
198 | do { \ |
199 | if (s->hassavedcoll) { \ |
200 | *h = s->savedcoll; \ |
201 | h->report_ID = c->report_ID; \ |
202 | s->hassavedcoll = 0; \ |
203 | return (1); \ |
204 | } \ |
205 | } while(0) |
206 | |
207 | static int |
208 | hid_get_item_raw(hid_data_t s, hid_item_t *h) |
209 | { |
210 | hid_item_t nc, *c; |
211 | unsigned int bTag, bType, bSize; |
212 | int32_t mask; |
213 | int32_t dval; |
214 | |
215 | if (s == NULL((void *)0)) |
216 | return (0); |
217 | |
218 | if (s->pushlevel >= MAXPUSH4) |
219 | return (0); |
220 | |
221 | c = &s->cur[s->pushlevel]; |
222 | |
223 | top: |
224 | /* check if there is an array of items */ |
225 | if (s->icount < s->ncount) { |
226 | REPORT_SAVED_COLLdo { if (s->hassavedcoll) { *h = s->savedcoll; h->report_ID = c->report_ID; s->hassavedcoll = 0; return (1); } } while (0); |
227 | /* get current usage */ |
228 | if (s->iusage < s->nusage) { |
229 | dval = s->usages_min[s->iusage] + s->ousage; |
230 | c->usage = dval; |
231 | s->usage_last = dval; |
232 | if (dval == s->usages_max[s->iusage]) { |
233 | s->iusage ++; |
234 | s->ousage = 0; |
235 | } else { |
236 | s->ousage ++; |
237 | } |
238 | } else { |
239 | /* Using last usage */ |
240 | dval = s->usage_last; |
241 | } |
242 | s->icount ++; |
243 | /* |
244 | * Only copy HID item, increment position and return |
245 | * if correct kindset! |
246 | */ |
247 | if (s->kindset & (1 << c->kind)) { |
248 | *h = *c; |
249 | h->pos = s->pos[c->kind]; |
250 | s->pos[c->kind] += c->report_size * c->report_count; |
251 | return (1); |
252 | } |
253 | } |
254 | |
255 | /* reset state variables */ |
256 | s->icount = 0; |
257 | s->ncount = 0; |
258 | s->iusage = 0; |
259 | s->nusage = 0; |
260 | s->susage = 0; |
261 | s->ousage = 0; |
262 | hid_clear_local(c); |
263 | |
264 | /* get next item */ |
265 | while (s->p != s->end) { |
266 | |
267 | bSize = hid_get_byte(s, 1); |
268 | if (bSize == 0xfe) { |
269 | /* long item */ |
270 | bSize = hid_get_byte(s, 1); |
271 | bSize |= hid_get_byte(s, 1) << 8; |
272 | bTag = hid_get_byte(s, 1); |
273 | bType = 0xff; /* XXX what should it be */ |
274 | } else { |
275 | /* short item */ |
276 | bTag = bSize >> 4; |
277 | bType = (bSize >> 2) & 3; |
278 | bSize &= 3; |
279 | if (bSize == 3) |
280 | bSize = 4; |
281 | } |
282 | |
283 | switch(bSize) { |
284 | case 0: |
285 | dval = 0; |
286 | mask = 0; |
287 | break; |
288 | case 1: |
289 | dval = (int8_t)hid_get_byte(s, 1); |
290 | mask = 0xFF; |
291 | break; |
292 | case 2: |
293 | dval = hid_get_byte(s, 1); |
294 | dval |= hid_get_byte(s, 1) << 8; |
295 | dval = (int16_t)dval; |
296 | mask = 0xFFFF; |
297 | break; |
298 | case 4: |
299 | dval = hid_get_byte(s, 1); |
300 | dval |= hid_get_byte(s, 1) << 8; |
301 | dval |= hid_get_byte(s, 1) << 16; |
302 | dval |= hid_get_byte(s, 1) << 24; |
303 | mask = 0xFFFFFFFF; |
304 | break; |
305 | default: |
306 | dval = hid_get_byte(s, bSize); |
307 | continue; |
308 | } |
309 | |
310 | switch (bType) { |
311 | case 0: /* Main */ |
312 | switch (bTag) { |
313 | case 8: /* Input */ |
314 | c->kind = hid_input; |
315 | c->flags = dval; |
316 | ret: |
317 | c->report_count = s->loc_count; |
318 | c->report_size = s->loc_size; |
319 | |
320 | if (c->flags & HIO_VARIABLE0x002) { |
321 | /* range check usage count */ |
322 | if (c->report_count > 255) { |
323 | s->ncount = 255; |
324 | } else |
325 | s->ncount = c->report_count; |
326 | |
327 | /* |
328 | * The "top" loop will return |
329 | * one and one item: |
330 | */ |
331 | c->report_count = 1; |
332 | c->usage_minimum = 0; |
333 | c->usage_maximum = 0; |
334 | } else { |
335 | s->ncount = 1; |
336 | } |
337 | goto top; |
338 | |
339 | case 9: /* Output */ |
340 | c->kind = hid_output; |
341 | c->flags = dval; |
342 | goto ret; |
343 | case 10: /* Collection */ |
344 | c->kind = hid_collection; |
345 | c->collection = dval; |
346 | c->collevel++; |
347 | c->usage = s->usage_last; |
348 | nc = *c; |
349 | if (s->hassavedcoll) { |
350 | *h = s->savedcoll; |
351 | h->report_ID = nc.report_ID; |
352 | s->savedcoll = nc; |
353 | return (1); |
354 | } else { |
355 | s->hassavedcoll = 1; |
356 | s->savedcoll = nc; |
357 | } |
358 | goto top; |
359 | case 11: /* Feature */ |
360 | c->kind = hid_feature; |
361 | c->flags = dval; |
362 | goto ret; |
363 | case 12: /* End collection */ |
364 | REPORT_SAVED_COLLdo { if (s->hassavedcoll) { *h = s->savedcoll; h->report_ID = c->report_ID; s->hassavedcoll = 0; return (1); } } while (0); |
365 | c->kind = hid_endcollection; |
366 | if (c->collevel == 0) { |
367 | /* Invalid end collection. */ |
368 | return (0); |
369 | } |
370 | c->collevel--; |
371 | *h = *c; |
372 | return (1); |
373 | default: |
374 | break; |
375 | } |
376 | break; |
377 | |
378 | case 1: /* Global */ |
379 | switch (bTag) { |
380 | case 0: |
381 | c->_usage_page = dval << 16; |
382 | break; |
383 | case 1: |
384 | c->logical_minimum = dval; |
385 | break; |
386 | case 2: |
387 | c->logical_maximum = dval; |
388 | break; |
389 | case 3: |
390 | c->physical_minimum = dval; |
391 | break; |
392 | case 4: |
393 | c->physical_maximum = dval; |
394 | break; |
395 | case 5: |
396 | c->unit_exponent = dval; |
397 | break; |
398 | case 6: |
399 | c->unit = dval; |
400 | break; |
401 | case 7: |
402 | /* mask because value is unsigned */ |
403 | s->loc_size = dval & mask; |
404 | break; |
405 | case 8: |
406 | hid_switch_rid(s, c, dval & mask); |
407 | break; |
408 | case 9: |
409 | /* mask because value is unsigned */ |
410 | s->loc_count = dval & mask; |
411 | break; |
412 | case 10: /* Push */ |
413 | if (s->pushlevel < MAXPUSH4 - 1) { |
414 | s->pushlevel++; |
415 | s->cur[s->pushlevel] = *c; |
416 | /* store size and count */ |
417 | c->report_size = s->loc_size; |
418 | c->report_count = s->loc_count; |
419 | /* update current item pointer */ |
420 | c = &s->cur[s->pushlevel]; |
421 | } |
422 | break; |
423 | case 11: /* Pop */ |
424 | if (s->pushlevel > 0) { |
425 | s->pushlevel--; |
426 | c = &s->cur[s->pushlevel]; |
427 | /* restore size and count */ |
428 | s->loc_size = c->report_size; |
429 | s->loc_count = c->report_count; |
430 | c->report_size = 0; |
431 | c->report_count = 0; |
432 | } |
433 | break; |
434 | default: |
435 | break; |
436 | } |
437 | break; |
438 | case 2: /* Local */ |
439 | switch (bTag) { |
440 | case 0: |
441 | if (bSize != 4) |
442 | dval = (dval & mask) | c->_usage_page; |
443 | |
444 | /* set last usage, in case of a collection */ |
445 | s->usage_last = dval; |
446 | |
447 | if (s->nusage < MAXUSAGE100) { |
448 | s->usages_min[s->nusage] = dval; |
449 | s->usages_max[s->nusage] = dval; |
450 | s->nusage ++; |
451 | } |
452 | /* else XXX */ |
453 | |
454 | /* clear any pending usage sets */ |
455 | s->susage = 0; |
456 | break; |
457 | case 1: |
458 | s->susage |= 1; |
459 | |
460 | if (bSize != 4) |
461 | dval = (dval & mask) | c->_usage_page; |
462 | c->usage_minimum = dval; |
463 | |
464 | goto check_set; |
465 | case 2: |
466 | s->susage |= 2; |
467 | |
468 | if (bSize != 4) |
469 | dval = (dval & mask) | c->_usage_page; |
470 | c->usage_maximum = dval; |
471 | |
472 | check_set: |
473 | if (s->susage != 3) |
474 | break; |
475 | |
476 | /* sanity check */ |
477 | if ((s->nusage < MAXUSAGE100) && |
478 | (c->usage_minimum <= c->usage_maximum)) { |
479 | /* add usage range */ |
480 | s->usages_min[s->nusage] = |
481 | c->usage_minimum; |
482 | s->usages_max[s->nusage] = |
483 | c->usage_maximum; |
484 | s->nusage ++; |
485 | } |
486 | /* else XXX */ |
487 | |
488 | s->susage = 0; |
489 | break; |
490 | case 3: |
491 | c->designator_index = dval; |
492 | break; |
493 | case 4: |
494 | c->designator_minimum = dval; |
495 | break; |
496 | case 5: |
497 | c->designator_maximum = dval; |
498 | break; |
499 | case 7: |
500 | c->string_index = dval; |
501 | break; |
502 | case 8: |
503 | c->string_minimum = dval; |
504 | break; |
505 | case 9: |
506 | c->string_maximum = dval; |
507 | break; |
508 | case 10: |
509 | c->set_delimiter = dval; |
510 | break; |
511 | default: |
512 | break; |
513 | } |
514 | break; |
515 | default: |
516 | break; |
517 | } |
518 | } |
519 | return (0); |
520 | } |
521 | |
522 | int |
523 | hid_get_item(hid_data_t s, hid_item_t *h) |
524 | { |
525 | int r; |
526 | |
527 | for (;;) { |
528 | r = hid_get_item_raw(s, h); |
529 | if (r <= 0 || s->reportid == -1 || h->report_ID == s->reportid) |
530 | break; |
531 | } |
532 | return (r); |
533 | } |
534 | |
535 | int |
536 | hid_report_size(report_desc_t r, enum hid_kind k, int id) |
537 | { |
538 | struct hid_data *d; |
539 | struct hid_item h; |
540 | uint32_t temp; |
541 | uint32_t hpos; |
542 | uint32_t lpos; |
543 | int report_id = 0; |
544 | |
545 | hpos = 0; |
546 | lpos = 0xFFFFFFFF; |
547 | |
548 | memset(&h, 0, sizeof h); |
549 | for (d = hid_start_parse(r, 1 << k, id); hid_get_item(d, &h); ) { |
550 | if (h.kind == k) { |
551 | /* compute minimum */ |
552 | if (lpos > h.pos) |
553 | lpos = h.pos; |
554 | /* compute end position */ |
555 | temp = h.pos + (h.report_size * h.report_count); |
556 | /* compute maximum */ |
557 | if (hpos < temp) |
558 | hpos = temp; |
559 | if (h.report_ID != 0) |
560 | report_id = 1; |
Value stored to 'report_id' is never read | |
561 | } |
562 | } |
563 | hid_end_parse(d); |
564 | |
565 | /* safety check - can happen in case of currupt descriptors */ |
566 | if (lpos > hpos) |
567 | temp = 0; |
568 | else |
569 | temp = hpos - lpos; |
570 | |
571 | /* No extra byte for the reportID because the kernel skips it. */ |
572 | return ((temp + 7) / 8); |
573 | } |
574 | |
575 | int |
576 | hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k, |
577 | hid_item_t *h, int id) |
578 | { |
579 | struct hid_data *d; |
580 | |
581 | for (d = hid_start_parse(desc, 1 << k, id); hid_get_item(d, h); ) { |
582 | if (h->kind == k && !(h->flags & HIO_CONST0x001) && h->usage == u) { |
583 | hid_end_parse(d); |
584 | return (1); |
585 | } |
586 | } |
587 | hid_end_parse(d); |
588 | h->report_size = 0; |
589 | return (0); |
590 | } |